Valve for bags



Jan. 5, 1943.

T. A CONTRYMA VALVE FOR BAGS Filed Sept. 21, 1938 Patented Jan. 5, 1943 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to an improvement in valves for bags, and has for its object to improve the closing of the valve, reduce the danger of leakage, and strengthen the closure of the end of the bag.

The invention is particularly adapted for use in a bag having its end closed by a sewed seam. Valves in such bags are customarily extended longitudinally of the bag while the bag is empty, but are spread laterally of the bag when the bag is filled. The valve closes most securely against leakage when the change in shape of the valve from its empty-bag position to its filled-bag position takes place about definite, predetermined fold lines, so that the closing lip of the valve lies smoothly against the end of the bag. One object of the invention is to facilitate this desired closing of the valve.

The valve comer of a bag is sometimes torn during, or at the close of, the filling operation. One of the objects of the invention is to increase the resistance of the valve corner to tearing without increasing the amount of material in the bag.

The manner in which the objects of the invention are achieved will appear as the description proceeds.

In the accompanying drawing, forming a part of this specification,

Figure 1 is a view of one corner of a bag with its sides spread apart and the corner turned in r to form a valve;

Fig. 2 shows the edges folded to embody the improvement herein claimed;

Fig. 3 is a view of the comer of the bag after the valve has been tucked in and the end closed, the bag wall being broken away to show the valve;

Fig. 4 is a section along the line 4-4 of Fig. 3, and showing the edge of the valve;

Fig. 5 is a view similar to Fig; 4, but showing the valve in partially closed position; and

Fig. 6 is a view similar to Fig. 3, but showing a modification of the manner of folding.

In the embodiment of the invention illustrated in the drawing, a gusseted bag tube In is spread apart and the comer ll turned in, as usual, to form a valve flap I2. In the form shown, the edge of the valve flap is provided with slots 13 and it. Originally, the corner where the valve is to be formed extends beyond the adjacent end of the bag walls, so as to provide an extended valve flap.

The improvement is produced by folding under about diagonal line l8, as shown in Fig. 2. When the sides of the bag are brought together and the end is closed by a seam 25, as shown in Figs.

3, 4 and 5, folded back portions l5 and I! are caught in the seam and increase the wall thick ness at this point.

The usual manner of filling such a bag is to hang it on a filling tube which is inserted through the valve opening. When the bag is. filled, it

comer I 5 about diagonal line l6,and comer ll places considerable stress upon the seam above the filling tube, and the bag sometimes yields to this stress. Turning back the edge of the valve lip, as described, not only provides an extra thickness at the point where the stress is greatest,-but also provides a fold at the edge of the valve at the seam, thereby increasing the resistance to tearing stress.

Also fold lines I 6 and I8 increase the resistance of the valve flap to bending along these lines. When the bag is empty, the valve collapses as shown in Figs. 3 and 4; but when the bag is filled, the walls of the bag spread and the lower edge of the valve flap is pressed upward towards the closing seam by the contents of the bag.

- Fig. 5 shows the valve in a partly closed position.

The valve is least likely to leak when the lower flap lies smoothly against the upper flap. It will be readily understood that the stiffened fold lines It and I8 increase the tendency for the flap to bend along lines l3 and I4 when the under flap is pressed upward, and decrease the danger of irregular crumpling of the edge of the valve. In fact, lines [6 and I8 act somewhat as stiffening rods, compelling the flap to bend along lines l3 and M as hinges, which are approximately half-way between seam 25 and middle line 26 of the valve.

It will be seen, therefore, that turning back corners l5 and I1 as described strengthens the valve corner and also aids in proper closure of the valve.

Folding back corners 20 and'22 about lines 2| and 23 respectively stifiens the flap along lines 2| and 23 and causes these. lines to act as toggles from fold line or hinge 26, spreading apart the hinges l3 and I! when the lower flap is pressed upward, and decreasing the danger of buckling and irregular crumpling of the lower lip of the valve.

It is preferred to fold the corners of the valve away from the filling opening as shown. Some of the objects of the invention would be accomplished by folding the valve edges into the filling passage, but this is not preferred because the infolded edges may catch on the-filling tube, and

corner [5' is shown folded about line I 8' in this way. Corner 20',may'be left unfolded, as shown, or may be folded about a continuation of line I 6',

or about any other line as desired. The type shown in Fig. 6 has the advantage of easy folding and of extending the folded corner farther into the seam, for strengthening purposes.

Under some circumstances, in a multl-ply bag, only part of the plies need be folded. It will be readily understood that other changes in the shape of the valve and folded back corners maybe made, and that such folds may be made at only part of the places indicated while retaining some advantages, and that various other departures may be made from the exact disclosure, the scope of the invention being indicated by the appended claims.

What I claim is:

l. A bag having a corner-turned in to form a valve flap and having the central portion of the flap extending straight into the bag for the full length of the flap and having the corners of the flap turned back and providing'fold lines along the inner edge of' the flap at each side of said central portion.

2. A bag having a corner turned in to form a valve flap and having a sewn seam closing the valve end of the bag, and the corners of the valve flap being turned under between the nap and the side wall of the bag and caught in the seam, thereby providing an extra thickness in the seams at the top of the valve.

3. A bag having a comer turned in to form a valve flap, the valve flap being shaped to close normally by folding about predetermined lines perpendicular to the inner edge of the flap, and having part of the edge of the flap turned back and forming a fold at the edge of the completed flap, said fold terminating at one end at one of said predetermined lines.

4. A bag having a comer turned in to form a valve flap, a sewed seam closing the end of the bag, the valve flap being shaped to close normally by folding about predetermined lines approxi mately parallel with the seam and midway between the seam and the center of the flap, and the corners of the flap being turned back toward the end of the seam, the lines about which the corners are folded forming the final edge of the valve flap running from the seam to, and terminating at, said predetermined lines.

5. A bag having a corner turned in to form a valve flap, 9. sewed seam closing the end of the bag, and the comers of the valve being turned in at the seam and about lines running diagonally from the seam to the inner edge of the flap.

6. A bag in accordance with claim 5, and having said lines terminate at the edge of the valve approximately half way between the seam and the middle of "the inner edge of the valve flap.

7. A bag in accordance with claim 5, and having said lines terminate at the edge of the valve flap approximately half way between th seam and the middle of the valve, and having the edges of the flap turned back about lines running from the edge of the valve at its middle point-diagonally backward to a point approximately half way between the seam and the middle of the valve.

8. A bag having a corner turned in to form a valve flap, a sewed seam closing the end of the bag, and each corner of the valve being turned in at the seam about a line running approximately parallel with the edge of the flap and for approximately half, and only approximately. half, the distance between the seam edge of the flap and the central line of the flap.

9. A paper bag having a valve flap that closes best when folded about predetermined lines approximately perpendicular to the inner edge of the flap, and having the edge of the flap folded back about a line running approximately at a right angle to, and terminating at, one of the first said lines.

10. A bag in accordance with claim 8 and having the last said line terminate at the inner edge of the valve closely adjacent one of the first said lines.

11. A multi-ply bag having a corner turned in to form a valve flap, and-having the central portion of the flap extending straight into the ba dicular to the inner edge of the fiap and the corners of the valve being turned in at the seam and about lines running diagonally from the seam to the inner edge of the flap.

13. A bag having a corner turned in to form a valve flap, a sewed seam closing the end of the bag, the valve flap being shaped to close normally by folding about predetermined lines perpendicular to the inner edge of the flap and the corners of the valve being turned in at the seam and about lines running diagonally from the seam to the inner edge of the-flap at a point about half way between the seam and the middle of the flap.

'I'HERON A. CO NTRYMAN.

CERTIFICATE OF cohmscflon. PatentNo. 2,507,111. January 5, 191 5.

THERON A. CONTRYHAN.

It is hereby certified that error Appears in the printed specification of the above n'umbered patent requiring correction as follows: Page 2, seeond'column, line 50, claim lo, for "claims? read --claim 9--; and that the said Letters Patent should be read 'with this correction therein that the same may conform to the record of the case in the Pjatent Office.

Signed and sealed this 16th 'day of February, A. D. 1915.

Henry Van Arsdale, seal) Acting Ccaumia's:sioner of Patents. 

